/* =====================================================================
* OrsonPDF : a fast, light-weight PDF library for the Java(tm) platform
* =====================================================================
*
* (C)opyright 2013-2015, by Object Refinery Limited. All rights reserved.
*
* Project Info: http://www.object-refinery.com/orsonpdf/index.html
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* [Oracle and Java are registered trademarks of Oracle and/or its affiliates.
* Other names may be trademarks of their respective owners.]
*
* If you do not wish to be bound by the terms of the GPL, an alternative
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package com.orsonpdf.util;
import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Graphics2D;
import java.awt.font.FontRenderContext;
import java.awt.font.LineMetrics;
import java.awt.geom.AffineTransform;
import java.awt.geom.Rectangle2D;
import java.text.AttributedString;
/**
* Text utility functions.
*/
public class TextUtils {
private TextUtils() {
// no need to instantiate this.
}
/**
* Draws a string such that the specified anchor point is aligned to the
* given {@code (x, y)} location.
*
* @param text the text.
* @param g2 the graphics device.
* @param x the x coordinate (Java 2D).
* @param y the y coordinate (Java 2D).
* @param anchor the anchor location.
*
* @return The text bounds (adjusted for the text position).
*/
public static Rectangle2D drawAlignedString(String text,
Graphics2D g2, float x, float y, TextAnchor anchor) {
Rectangle2D textBounds = new Rectangle2D.Double();
float[] adjust = deriveTextBoundsAnchorOffsets(g2, text, anchor,
textBounds);
// adjust text bounds to match string position
textBounds.setRect(x + adjust[0], y + adjust[1] + adjust[2],
textBounds.getWidth(), textBounds.getHeight());
g2.drawString(text, x + adjust[0], y + adjust[1]);
return textBounds;
}
/**
* A utility method that calculates the anchor offsets for a string.
* Normally, the {@code (x, y)} coordinate for drawing text is a point on
* the baseline at the left of the text string. If you add these offsets to
* {@code (x, y)} and draw the string, then the anchor point should
* coincide with the {@code (x, y)} point.
*
* @param g2 the graphics device (not {@code null}).
* @param text the text.
* @param anchor the anchor point.
*
* @return The offsets.
*/
private static float[] deriveTextBoundsAnchorOffsets(Graphics2D g2,
String text, TextAnchor anchor) {
float[] result = new float[2];
FontRenderContext frc = g2.getFontRenderContext();
Font f = g2.getFont();
FontMetrics fm = g2.getFontMetrics(f);
Rectangle2D bounds = getTextBounds(text, g2, fm);
LineMetrics metrics = f.getLineMetrics(text, frc);
float ascent = metrics.getAscent();
float halfAscent = ascent / 2.0f;
float descent = metrics.getDescent();
float leading = metrics.getLeading();
float xAdj = 0.0f;
float yAdj = 0.0f;
if (anchor.isHorizontalCenter()) {
xAdj = (float) -bounds.getWidth() / 2.0f;
} else if (anchor.isRight()) {
xAdj = (float) -bounds.getWidth();
}
if (anchor.isTop()) {
yAdj = -descent - leading + (float) bounds.getHeight();
} else if (anchor.isHalfAscent()) {
yAdj = halfAscent;
} else if (anchor.isHalfHeight()) {
yAdj = -descent - leading + (float) (bounds.getHeight() / 2.0);
} else if (anchor.isBaseline()) {
yAdj = 0.0f;
} else if (anchor.isBottom()) {
yAdj = -metrics.getDescent() - metrics.getLeading();
}
result[0] = xAdj;
result[1] = yAdj;
return result;
}
/**
* A utility method that calculates the anchor offsets for a string.
* Normally, the {@code (x, y)} coordinate for drawing text is a point on
* the baseline at the left of the text string. If you add these offsets to
* {@code (x, y)} and draw the string, then the anchor point should
* coincide with the {@code (x, y)} point.
*
* @param g2 the graphics device (not {@code null}).
* @param text the text.
* @param anchor the anchor point.
* @param textBounds the text bounds (if not {@code null}, this
* object will be updated by this method to match the
* string bounds).
*
* @return The offsets.
*/
private static float[] deriveTextBoundsAnchorOffsets(Graphics2D g2,
String text, TextAnchor anchor, Rectangle2D textBounds) {
float[] result = new float[3];
FontRenderContext frc = g2.getFontRenderContext();
Font f = g2.getFont();
FontMetrics fm = g2.getFontMetrics(f);
Rectangle2D bounds = getTextBounds(text, g2, fm);
LineMetrics metrics = f.getLineMetrics(text, frc);
float ascent = metrics.getAscent();
result[2] = -ascent;
float halfAscent = ascent / 2.0f;
float descent = metrics.getDescent();
float leading = metrics.getLeading();
float xAdj = 0.0f;
float yAdj = 0.0f;
if (anchor.isHorizontalCenter()) {
xAdj = (float) -bounds.getWidth() / 2.0f;
} else if (anchor.isRight()) {
xAdj = (float) -bounds.getWidth();
}
if (anchor.isTop()) {
yAdj = -descent - leading + (float) bounds.getHeight();
} else if (anchor.isHalfAscent()) {
yAdj = halfAscent;
} else if (anchor.isHalfHeight()) {
yAdj = -descent - leading + (float) (bounds.getHeight() / 2.0);
} else if (anchor.isBaseline()) {
yAdj = 0.0f;
} else if (anchor.isBottom()) {
yAdj = -metrics.getDescent() - metrics.getLeading();
}
if (textBounds != null) {
textBounds.setRect(bounds);
}
result[0] = xAdj;
result[1] = yAdj;
return result;
}
/**
* Returns the bounds for the specified text.
*
* @param text the text ({@code null} permitted).
* @param g2 the graphics context (not {@code null}).
* @param fm the font metrics (not {@code null}).
*
* @return The text bounds ({@code null} if the {@code text}
* argument is {@code null}).
*/
public static Rectangle2D getTextBounds(String text, Graphics2D g2,
FontMetrics fm) {
double width = fm.stringWidth(text);
double height = fm.getHeight();
return new Rectangle2D.Double(0.0, -fm.getAscent(), width, height);
}
/**
* Draws a string that is aligned by one anchor point and rotated about
* another anchor point.
*
* @param text the text.
* @param g2 the graphics device.
* @param x the x-coordinate for positioning the text.
* @param y the y-coordinate for positioning the text.
* @param textAnchor the text anchor.
* @param angle the rotation angle.
* @param rotationX the x-coordinate for the rotation anchor point.
* @param rotationY the y-coordinate for the rotation anchor point.
*/
public static void drawRotatedString(String text, Graphics2D g2, float x,
float y, TextAnchor textAnchor, double angle,
float rotationX, float rotationY) {
if (text == null || text.equals("")) {
return;
}
float[] textAdj = deriveTextBoundsAnchorOffsets(g2, text, textAnchor);
drawRotatedString(text, g2, x + textAdj[0], y + textAdj[1], angle,
rotationX, rotationY);
}
/**
* Draws a string that is aligned by one anchor point and rotated about
* another anchor point.
*
* @param text the text.
* @param g2 the graphics device.
* @param x the x-coordinate for positioning the text.
* @param y the y-coordinate for positioning the text.
* @param textAnchor the text anchor.
* @param angle the rotation angle (in radians).
* @param rotationAnchor the rotation anchor.
*/
public static void drawRotatedString(String text, Graphics2D g2,
float x, float y, TextAnchor textAnchor,
double angle, TextAnchor rotationAnchor) {
if (text == null || text.equals("")) {
return;
}
float[] textAdj = deriveTextBoundsAnchorOffsets(g2, text, textAnchor);
float[] rotateAdj = deriveRotationAnchorOffsets(g2, text,
rotationAnchor);
drawRotatedString(text, g2, x + textAdj[0], y + textAdj[1],
angle, x + textAdj[0] + rotateAdj[0],
y + textAdj[1] + rotateAdj[1]);
}
/**
* A utility method that calculates the rotation anchor offsets for a
* string. These offsets are relative to the text starting coordinate
* ({@code BASELINE_LEFT}).
*
* @param g2 the graphics device.
* @param text the text.
* @param anchor the anchor point.
*
* @return The offsets.
*/
private static float[] deriveRotationAnchorOffsets(Graphics2D g2,
String text, TextAnchor anchor) {
float[] result = new float[2];
FontRenderContext frc = g2.getFontRenderContext();
LineMetrics metrics = g2.getFont().getLineMetrics(text, frc);
FontMetrics fm = g2.getFontMetrics();
Rectangle2D bounds = TextUtils.getTextBounds(text, g2, fm);
float ascent = metrics.getAscent();
float halfAscent = ascent / 2.0f;
float descent = metrics.getDescent();
float leading = metrics.getLeading();
float xAdj = 0.0f;
float yAdj = 0.0f;
if (anchor.isLeft()) {
xAdj = 0.0f;
} else if (anchor.isHorizontalCenter()) {
xAdj = (float) bounds.getWidth() / 2.0f;
} else if (anchor.isRight()) {
xAdj = (float) bounds.getWidth();
}
if (anchor.isTop()) {
yAdj = descent + leading - (float) bounds.getHeight();
} else if (anchor.isHalfHeight()) {
yAdj = descent + leading - (float) (bounds.getHeight() / 2.0);
} else if (anchor.isHalfAscent()) {
yAdj = -halfAscent;
} else if (anchor.isBaseline()) {
yAdj = 0.0f;
} else if (anchor.isBottom()) {
yAdj = metrics.getDescent() + metrics.getLeading();
}
result[0] = xAdj;
result[1] = yAdj;
return result;
}
/**
* A utility method for drawing rotated text.
* <P>
* A common rotation is {@code -Math.PI/2} which draws text 'vertically'
* (with the top of the characters on the left).
*
* @param text the text.
* @param g2 the graphics device.
* @param angle the angle of the (clockwise) rotation (in radians).
* @param x the x-coordinate.
* @param y the y-coordinate.
*/
public static void drawRotatedString(String text, Graphics2D g2,
double angle, float x, float y) {
drawRotatedString(text, g2, x, y, angle, x, y);
}
/**
* A utility method for drawing rotated text.
* <P>
* A common rotation is {@code -Math.PI/2} which draws text 'vertically'
* (with the top of the characters on the left).
*
* @param text the text.
* @param g2 the graphics device.
* @param textX the x-coordinate for the text (before rotation).
* @param textY the y-coordinate for the text (before rotation).
* @param angle the angle of the (clockwise) rotation (in radians).
* @param rotateX the point about which the text is rotated.
* @param rotateY the point about which the text is rotated.
*/
public static void drawRotatedString(String text, Graphics2D g2,
float textX, float textY, double angle,
float rotateX, float rotateY) {
if ((text == null) || (text.equals(""))) {
return;
}
final AffineTransform saved = g2.getTransform();
// apply the rotation...
AffineTransform rotate = AffineTransform.getRotateInstance(angle,
rotateX, rotateY);
g2.transform(rotate);
AttributedString as = new AttributedString(text,
g2.getFont().getAttributes());
g2.drawString(as.getIterator(), textX, textY);
g2.setTransform(saved);
}
}